The use of a retaining ring to axially secure a coupling nut to a tubular member is generally known in the art. Examples of such arrangements are disclosed in British patent specification 349,329 and U.S. Pat. Nos. 2,383,959; 2,657,078; 2,960,359; 3,446,552; and 3,853,413. Coupling nuts are generally used to connect a tubular member or backshell, used for terminating an electrical cable shield, to an electrical connector. More specifically, some electrical cables are provided with an outer woven metallic shield for protecting the conductors within the electrical cable from electromagnetic interference. The woven metalic shield generally surrounds all the conductors in the electical cable and is terminated to the tubular member. The tubular member is formed with an annular shoulder at one end which forms a bearing surface for the retaining ring. The retaining ring is received in an interior annular groove formed at one end of the coupling nut. The other end of the coupling nut is threaded to allow it to be screwed into an electrical connector forming an electrical connector assembly.
In some known applications, a metal retaining ring, such as steel, is used while the other components are formed from composite materials. The use of a steel retaining ring can cause various problems. For example, it can damage the plating on the composite components and expose the base polymer. Once the base polymer is exposed, the components will be susceptible to damage from certain chemicals or fluids in the environment of the assembly. The plating loss can also cause a loss of electrical conductivity and the danger of shavings falling into the electrical connector or other nearby electrical components. Also it is known that a metal retaining ring can cause harmful grooves in the composite components which result in stress zones.
Another problem associated with electrical connector assemblies is that in some applications, such assemblies may be subject to a substantial amount of vibration. Such vibration can cause rotation of the coupling nut with respect to the tubular member. Such rotation can cause damage to the electrical conductor terminations at the electrical connector.
Various means are known in the art to restrict a coupling nut from rotating with respect to a tubular member. For example, various anti-decoupling means are disclosed in U.S. Pat. Nos. 4,007,953; 4,074,927; 4,165,910; 4,235,498; 4,109,990; 4,268,103; 4,457,469; 4,484,790; 4,487,470; 4,497,530; 4,502,748; 4,519,661; 4,531,801; and 4,648,670.
In Brush et al, U.S. Pat. No. 4,502,748 an electrical connector is disclosed having a coupling nut and a leaf spring mounted on an interior portion of a coupling nut. The leaf spring is provided with a radially inwardly extending tooth which engages an angular slot formed on a cooperating ring. The engagement of the tooth with the slot restricts rotation of the coupling nut with respect to the ring.
Ratchet type anti-decoupling means are also known. In this type of device, the tubular member is formed with an annular shoulder at one end. The annular shoulder is formed with a plurality of ratchet teeth which cooperate with a radially inwardly disposed tooth or protuberance formed on a leaf spring and disposed in a coupling nut. The protuberance cooperates with the ratchet teeth to prevent the coupling nut from freely spinning with respect to the tubular member.
U.S. Pat. No. 4,648,670 also discloses a ratchet type anti-decoupling means, similar to that described above, but which utilizes a gull-wing shaped leaf spring having a central portion and two depending wing portions extending outwardly therefrom. The gull-wing shaped leaf spring is attached to the inside of the coupling nut and includes a radially inwardly disposed protuberance or tooth on each wing portion which cooperate with ratchet teeth.
Although the use of anti-decoupling means including ratchet type is generally known, none of the patents above disclose a structure which allows the coupling nut and the retaining ring to be installed from the front (e.g., over the toothed annular shoulder formed on the tubular member) which facilitates assembly of tubular members having a termination surface with a relatively larger diameter than the inner diameter of the coupling nut and for tubular members formed with 45 and 90 degree angles which generally would not permit the coupling nut ring to be installed from the rear.